People who do not want to pay zakat, what is the law?
In Islam, Muslims are required to pay their zakat. For that, if there are Muslims who refuse to pay zakat, what is the law?
People who don't pay because they have renounced their obligations zakat
Whoever does not want to pay zakat because he has denied the obligation of zakat, he has kafir. That is, out of Islam. The reason is, he has been denying Allah's law, denying verses and hadiths that are shariah (obviously) oblige zakat.
Even in Mughni al-Muhtaj it is mentioned that though muzakki pay zakat, if his heart denies the obligation of zakat then he has left Islam. Of course this should be a concern for every Muslim.
People who don't want to pay zakat are not reneging
If he still believes in the obligation of zakat, it's just that he has objections to setting aside part of his wealth for zakat and refuses to pay it, then he is still declared a Muslim, but his deed is considered a grave sin. Allah Ta'ala threatened him with a painful torment of hell, as explained in His words:
(والذين يكنزون الذهب والفضة ولا ينفقونها فى سبيل الله فبشرهم بعذاب أليم () يوم يحمى عليها فى نار جهنم فتكوى بها جبابهم وجنوبهم وظهورهم هذا ما كنزتم لأنفسكم فذوقوا م كنتم تكنزون ()) (التوبة: 34-35)
Meaning: "And those who keep gold and silver and do not spend it in the way of Allah, then tell them, that they will get a painful torment. On the day that the gold and silver are heated in Hell Hell then burnt with it their foreheads, stomachs and backs (then it is said) to them: "This is your treasure which you keep for yourself, so feel now (the result of) what you have kept it" (Surah At-Taubah: 34-35).
